Hyn Patty

Thank you!  Speaking of Fabio tails... With a really complex tail such as my hairy Pasture Porthos sports I may well need to cut the tail into at least two pieces and have quite a few mold pieces /and/ still have to flood, then redetail, some of the undercuts.  Oh well!  This boy will be my most challenging piece to mold to date (this is a 3D print that is mirrored to face the other direction and a different size).  For now I am cheating.  I sent this boy and his larger version off to England to be molded and cast in bone china bisque for me.  But I will be playing with cutting one up here in studio and trying to mold that tail myself just for the challenge.  BUT at least I know he'll be in production in time for Breyerfest in July even if it takes me a while to mold and cast this version on my side of the pond.
For scale I can do pretty much anything I want within the limits of my 3D printers and the quality of my scans.  Or in the case of the spider foal - larger than 'traditional' scale because I'm doing that one BIGGER than usual.  But 'traditional' scale is what most equine bronzes are normally produced in - 1/9th scale to the real horse.  Larger than traditional is usually about 1/6th scale.  Classic is about 1/12th, etc on down or on up!  Some of these scales are used so often for equine art that they have names (though often more than one name for any given size).  Porthos is considered 1/9th scale, which usually is about 7 inches tall.  But as he's a draft horse who's taller and larger his scaling down to 1/9th came to 8 inches tall.  Of course he'll shrink a bit in each ceramic media, that's just his resin size.    If you do internet searches you can find various 'model scales' or 'model horse scales' to compare.
'Venti' scale Pasture Porthos is a little smaller than 'classic' scale at 1/15th is shown with the larger roto cast white resin that is 1/9th 'traditional' scale.  Then micros are about 1/40th scale (around 1.5" tall).  Curio falls in around 1/20th scale for comparison (not pictured here).

Noted.  And sometimes I use IPA - depends which one is handier.  I've never had an issue with either one since I literally only use a drop or so in my water spray bottle of the bleach.  The generic bleach I buy only lists one ingredient and nothing added for scent.  (I also incidentally use it for phytosanitary applications like tissue culture of plant materials.)
Yes!  This method of cutting up the piece is typical for casting porcelain and bone china in the UK and Europe.  Indeed it was a few photos shared here with me from another member (who may or may not wish to be named) that helped me figure out this problem.  I also worked with porcelain sometimes and I've been working on perfecting and testing English bone china slip I've made here in my studio.  So I went ahead and produced this multi-part mold for that purpose.  It works just as well for earthenware. 
As I knock some rust off I'll be pushing to try and make more complex molds that would allow me to cast Porthos as whole and as close to one piece as possible.  Body with three legs attached most likely, with the head and neck separate and that cocked back leg.  That would take less assembly and thus less time.  And problem solving with mold making is an excellent challenge to practice if you want to get better anyway.
One of my new sculptures I have started is the 'Spider foal' that is rolling.   I'm jokingly calling it my 'spider' sculpture for now because it looks hideous!  But it's in the early 'skeleton' stage where I flesh out the proportions of the bones and set the joints as points of reference from which I will build up tendons, muscle, skin, etc over top.  Anyway, you can see that I do not like to sculpt with molding limitations in mind.  So being able to mold them in pieces and assemble ANY kind of pose or complex arrangement really frees me up to do anything I want.  

Now, to give you a sense of what 'curio' scale means here is the same bisque shown in my hand.  Here I have airbrushed on underglaze in greys and black and I am now dappling him.  Once fired with a clear glaze over this underglaze, he will be a dappled grey!  This is a sales piece that I will be offering at auction probably next weekend while I'm at a live show event.  But for now there's a lot of work to do to him to get him ready to be the new sample of my sculpture in ceramic!  I'll post more photos as I go so you all can see the finished boy when he's done.  I work in many layers, fire a number of times, and will also work in over glazes.  The upright mane ribbons will be added later after he's completed and are going to be enameled metal but I haven't finished making them yet.  They each fit down into little  holes I have drilled down his neck.
I am also making mold pieces for a larger 'traditional' scale version of this boy that stands about 8 inches tall.  I hope to have that one casting by June in time for a huge international event I'm attending in July at the Kentucky Horse Park in Lexington, KY.

This is Porths, my first version of this sculpture I started way back about 2007, almost completed in 2009 before illness derailed my studio for a while.  At any rate, I FINALLY finished this boy last year and released him in a resin edition.  I've since gone on to do a 'hairy' Pasture Porthos who's a bit chunkier, and with more feather, thicker legs, long mane and swishy Fabio tail who's casting in a resin edition this year.
Anyway, I've been busting butt to make MOLDS for these two versions of my Porthos sculpture.  Currently I am having the hairy Pasture Porthos molded and cast in England in fine bone china, though I'm also about to start testing slip and settlers for fine bone china pieces here in my studio later this year.  Meanwhile I'm focusing first on using finely ball milled earthenware with talc to cast some pieces.  This first one I've molded right here in studio is what we call Curio scale, a large mini in size.  He's my test cast to see if my mold worked (it did first try!) and to help me figure out how I want to rework and clean up my mold pieces to work even better.  Then I'll be making rubber molds starting next week of each plaster mold piece so I'll have a master from which to cast as many plaster replacement molds as I ever will want, later.
So here's my first ceramic bisque of Porthos with his original docked tail version (mane flights to be added later), an American Percheron with tail bows.

Here is the completed piece all glazed up.  All work has been done in the kiln, completed with satin glaze and minimal china painting.  The only thing on him that isn't ceramic media are his mane flights which are enameled metal, inset with pins into tiny holes along his neck.  Completed to a light dappled grey and with an optional base I have made for him to be affixed to, this piece will be posted to public auction.  He measures 3.75" inches tall and will be a unique color and variety in an edition of not more than probably 20 or so variations.  Once I have finished editing his photos and he has been sold at auction, I'll add a photo to my gallery album with him standing on his base.
Tada!  So now you know how I make my equine fine art sculpture in ceramics.  This one earthenware but I also work in porcelain and fine bone china.
 

I'm sure we have had this discussion a few years back, but good to return to it for those newbies out there. Over the years I have used all three, and found that I prefer the Magic Water. When teaching HS in the early years, I had used slip as that is what I learned to work with. If you you were diligent about your scoring, and your paddling/compressing the seams along with regular gap filling and smoothing you would have a good seam with no problems. However, being lax in any way could leave a seam that would split, or leave and ugly hole to be noticed even after glaze firing. Students took a long time to discover diligence. Vinegar was the addition that I started adding to my slip containers, as the mild acid did help to work the seams better. However, I came to believe that it was too easy for students to cover up a bad seam with slip of any sort than to get the seam right.  Along came Magic Water, and when I started using it myself, I knew that I had to start using it in the classroom. It did not change everything, but worked wonders with making seams and at the same time it was hard to hide a bad seam.
QotW: Slip, Slip with vinegar, Magic Water: What is your choice, and why?
 
best,
Pres

Copper is interesting and there are limits but most often found in an industrial setting when testing for heavy metals.. Sounds like you need a real environmental air test and lab analysis to figure this out ……… then figure out the source. Clay may or may not be a concern here so a real test with real quantities of constituents likely is the best way to know with reasonable certainty. For now, no exposure or very limited exposure until you can correct seems important. Adding cleaning chemicals, moisture etc… can amplify effects. I suggest get  a real test and lab analysis ……. on paper by an industrial hygienist or equivalent.

The one I'm testing now I found on Instagram and is this one and can be fired to whatever the base clay requires that you use:
This recipe is for repairing cracked bisque before a glaze firing.
add: 1 cup your clay slurry
Add: about 1/4 cup shredded toilet paper
Add: 1 1/2 TB vinegar. Any vinegar will do.
Blend with an emulsion blender stick. Don’t skip this step.
It should be the consistency of coarse toothpaste.
You can add more paper to make it harder or more vinegar to make it pastier.
Pack it into the crack. When it has dried dry sand it smooth. Glaze as usual.
 

I have mixed up the "Magic Water" recipe and it works. One gallon water, 9.5 gm sod silicate, 3 gm soda ash. 
Soda ash is quite caustic so make sure to wear gloves, or a glove, if you have a cut on your hand. It does sting otherwise.
If I recall the "clay" content was 2/3 clay powder and 1/3 toilet paper.

If you want soda ash (or your soda ash is old and has absorbed moisture) bake it in the oven at 200F for an hour if it's a small amount and it will then be soda ash.
I've tried the magic water + slip + paper pulp, didn't work for me.  I think it makes a difference what type of crack it is though. 

Sounds like you need to get the /air/ tested in your home.  Find out what it /is/ that you are smelling.  Mold, mildew, sewage, gas, etc?  Then you can have a home inspector help you locate the source of the problem.  As stated, it may have something to do with a clay foundation or nothing at all, but anything that is a health hazard like that needs to be addressed by a professional quickly who can first give you an air analysis, not guesses.  It sounds like you shouldn't even be in the home until you find out what is the issue.  Some molds for example and sewage can be life threatening issues.  As for the clothes?  Until you know what is making the smell you won't know how or if it /can/ be removed.   And that is the least of the problem.  Good luck with this and I hope you will sort it out quickly!

I second Peter's suggestions on this one.  I bisque fire all of my porcelains and bone china before I glaze (if I didn't acquire it already bisqued).  But then I also tend to use airbrushed underglazes with clear glazes over top so getting the glaze to stick has never been an issue for me.  It's not brush applied.  As said though, that presents other issues like a ventilated and filtered spray booth and suitable P100 type mask due to spraying silica, etc.    But with this form I think you are going to get the distortion without proper supports even in your bisque fire without glaze.  I'm not as knowledgeable about pottery though.  I work with sculpture so it's a slightly different beast.

Most hobby porcelains fire to mature bisque at cone 6.  But I'm with the rest of you - if she doesn't KNOW for absolute certain, I probably wouldn't put it in /my/ kilns.   If she's going to be producing several of these maybe she should just get herself a small kiln.  A used one if need be, and just learn how to do it herself.   She is also going to need to figure out how she's going to support them with props (settles) and they should be made out of the very same porcelain clay if she has enough left.  So yeah, maybe more complicated than she realized.  A lower soft fire may be wise but it won't make them as nice.  

Try a google for paperclay nest, then click on the images option. It may at least give an idea of the state-of-the-art.
Hits include
https://www.google.com/url?sa=i&url=https%3A%2F%2Fdeniserouleau.com%2Fworkshops%2Fadventuresinpaperclay&psig=AOvVaw24dMc2zyf9RW6-ztQqTML1&ust=1711619956846000&source=images&cd=vfe&opi=89978449&ved=2ahUKEwj2n7Wtl5SFAxUqVKQEHdaCBYoQr4kDegQIARBi

 
https://judithrosenthal.com/section/125628-Sticks and Stones.html

 
https://judithrosenthal.com/section/125628-Sticks and Stones.html

Yes, but it may introduce more problems than it solves.
To my untutored eye it looks like firing with a sitter would probably solve your slumping issues.

... but would introduce glazing issues.
The classic bone china solution uses a supported high-fire bisque and an unsupported lower-fire glaze, which creates its own problems.
Bone China https://digitalfire.com/glossary/bone+china
The process is completely different than what a potter would do: Bisque fire, glaze, high fire. Bone china is bisque fired to high fire and then glazed at a very low temperature. Since the porcelain has zero porosity, getting a glaze to stick and dry on it is not easy, the process needed goes well beyond what a normal potter would be willing to do.
PS
Balancing slumping and decoration has a long history. Robert Tichane expressed his surprise when he finally realised that the ancient Chinese cup he regularly drank from had a guilded rim to disguise the lack of glaze on the rim (a result of firing the cup rim-down to minimise slumping). 
I'm having difficulty visualising your "handmade leather molds". I assume that they are semi-flexible press-moulds, but am unsure how you extract the bowl from the mould.

Chiming in a little late on this one, but you mentioned the crack in your piece happening at another studio, where the bisque cycle is unknown to you. I strongly suspect the cause wasn’t the fact that it was bisqued twice, more that the cycle used was likely not suitable for your piece. Two foot pieces are going to need a slower cycle than regular pieces, just due to sheer thermal mass.  If the studio’s usual bisque cycle didn’t take that into account, or the kiln pack wasn’t a particularly heavy or even, that would be the most likely explanation to me.
Side note: I just spent the morning going through Ceramic Materials Workshop’s new commercial clay body analysis resource. It’s free if anyone wants to check it out for themselves. So far the submissions are limited to assorted clays in the US that are in the roughly cone 6-10 range. Bill’s statement that clays will shrink upon a second bisque depend greatly on what the first bisque temperature was, and which clay body is in question. If you’re bisquing to a common 06 temperature, the statement of a less than 1% increase is likely enough. If your usual bisque is higher or lower, it might not be. After about 1000*C (roughly cone 04) many clay bodies hold steady for a time before continuing to shrink. If you bisque very low to cone 020, the shrinkage charts actually decrease for a time, meaning the piece expands a bit after the carbonates and chemical water burn off. 
Again, this is VERY clay body dependent. 
 
 
 

Slow. Both for firing up and cooling down.
These pictures are from Digitalfire of lowfire ware, pots have cracked from uneven cooling, edges will have cooled faster than the middle area of the pieces. The way to avoid this is to have the cooling down go as evenly as possible. Slow the cooling down between 1150F - 950F, I go at 100F/hour through this zone with suspect work.

 There is negligible shrinkage, ie less than 1% between bone dry greenware and bisque firing to ^06- ^04, would be interesting to see data that shows refiring to a lower temp causes more shrinkage.
edit: when having your piece in the kiln put it between shelves, not at the top or bottom of the kiln, this helps the heat even out also. I put rectangular or triangular kiln posts around the outside edge of the shelf also. (round posts can roll)
 

One thing that comes to my mind for large pieces,  is it will shrink and grab on the shelf. The rim and likely the grid if flush at the bottom will tend to drag on the kiln shelf. The grid itself if not reasonably even could also cause this to warp and bend depending on variance in thickness and construction.  A waster slab and thin even silica beneath and between comes to mind to keep it smoothly moving and from grabbing. Same for glaze firing, although predicting distortion I think is tough without having tested a few shapes and if glazing only one side could deform the shape. Sounds like you can glaze both to a large extent. Quartz inversion (IMO)  is almost not a thing as every piece in every firing goes through it twice each firing the world around (probably millions of pieces). Having said that a reasonable slow speed helps with the rate it shrinks and there is no reason to go to cone 04 so neither of those suggestions sounds silly. We do multiple bisques with layer applications of underglaze but always bisque to lesser temps just to set each layer of underglaze.  There is no reason to waster the energy or stress the piece.

Yes!  I've gone off and on to Breyerfest since the mid 90's and that is indeed the event I am attending this year in July.  So I want to have a few of these in both sizes and both main versions produced in time to take with me.  I'm also flying out to California to judge a show of equine art and of course want to take some there too.   I also do a number of fine art shows once in a long while but shipping can be VERY costly and I have moved away from paying gallery and show commissions on my sales.  I get plenty of people willing to fight over the pieces I post to public auctions online.
Thank you both for your kind words.  I would love to see your dog pieces, Denise!  I used to sculpt a few dogs as well so if I ever have time I plan to get back to doing that once in a while in between equine pieces.
You are right Jeff that molding a piece like Porthos /can/ be crazy - if I was determined to cast him entirely in one piece, whole.  The issue of his sharply turned head and neck, and the close proximity of his back cocked leg that actually crosses over partly in front of his other back leg, would be ... very challenging to say the least.   So I cut up my 'master' I was molding and I actually cast Porthos in a few pieces.  With practice, assembly and clean up of such a sculpture goes pretty quickly.  I can demold the pieces into a wet box, allow them to firm up a bit, then do the old score and slip-stick routine.  Since I'm the sculptor it is no trouble whatsoever for me then to clean up and redetail those areas I had to attach.  That way it's actually not that difficult to mold such a sculpture as long as you don't mind some assembly.  I can easily put a piece like this together and do all the initial clean up and resculpting in about an hour or less.  Then back into the wet box for slow drying to prevent cracking as he has some uneven thickness in some areas.
To facilitate easier molding I can also flood some minor undercuts such as the tail bow, and simply go back and hand detail those pieces again after casting and assembly.  It does mean I spend a lot of time with post casting but on the other hand I get thousands of dollars per piece once completed so it's well worth my time to make them the highest possible quality I can. 

Now, to give you a sense of what 'curio' scale means here is the same bisque shown in my hand.  Here I have airbrushed on underglaze in greys and black and I am now dappling him.  Once fired with a clear glaze over this underglaze, he will be a dappled grey!  This is a sales piece that I will be offering at auction probably next weekend while I'm at a live show event.  But for now there's a lot of work to do to him to get him ready to be the new sample of my sculpture in ceramic!  I'll post more photos as I go so you all can see the finished boy when he's done.  I work in many layers, fire a number of times, and will also work in over glazes.  The upright mane ribbons will be added later after he's completed and are going to be enameled metal but I haven't finished making them yet.  They each fit down into little  holes I have drilled down his neck.
I am also making mold pieces for a larger 'traditional' scale version of this boy that stands about 8 inches tall.  I hope to have that one casting by June in time for a huge international event I'm attending in July at the Kentucky Horse Park in Lexington, KY.

This is Porths, my first version of this sculpture I started way back about 2007, almost completed in 2009 before illness derailed my studio for a while.  At any rate, I FINALLY finished this boy last year and released him in a resin edition.  I've since gone on to do a 'hairy' Pasture Porthos who's a bit chunkier, and with more feather, thicker legs, long mane and swishy Fabio tail who's casting in a resin edition this year.
Anyway, I've been busting butt to make MOLDS for these two versions of my Porthos sculpture.  Currently I am having the hairy Pasture Porthos molded and cast in England in fine bone china, though I'm also about to start testing slip and settlers for fine bone china pieces here in my studio later this year.  Meanwhile I'm focusing first on using finely ball milled earthenware with talc to cast some pieces.  This first one I've molded right here in studio is what we call Curio scale, a large mini in size.  He's my test cast to see if my mold worked (it did first try!) and to help me figure out how I want to rework and clean up my mold pieces to work even better.  Then I'll be making rubber molds starting next week of each plaster mold piece so I'll have a master from which to cast as many plaster replacement molds as I ever will want, later.
So here's my first ceramic bisque of Porthos with his original docked tail version (mane flights to be added later), an American Percheron with tail bows.

So much care and thought has come from long experience and patience. Porthos are sculptures to be proud of and that mane is really impressive! Thanks for sharing more details. 

Do you have photos of the Akita or the mold by chance?  I don't do the ball and socket thing but nice idea.  If I want to move a leg around I'm just going to resculpt it (and possibly make a mold of the leg to cast it for reuse later) and then sculpt the new attachment as needed as well.  I've already sculpted and molded some alternate pieces for another neck and leg, and I'm going to do an alternate body that's not so bent so I can do the head and neck in other positions.  Just for fun variations!  I get bored easily so it is very tedious for me to do the same thing over and over again...

Noted.  And sometimes I use IPA - depends which one is handier.  I've never had an issue with either one since I literally only use a drop or so in my water spray bottle of the bleach.  The generic bleach I buy only lists one ingredient and nothing added for scent.  (I also incidentally use it for phytosanitary applications like tissue culture of plant materials.)
Yes!  This method of cutting up the piece is typical for casting porcelain and bone china in the UK and Europe.  Indeed it was a few photos shared here with me from another member (who may or may not wish to be named) that helped me figure out this problem.  I also worked with porcelain sometimes and I've been working on perfecting and testing English bone china slip I've made here in my studio.  So I went ahead and produced this multi-part mold for that purpose.  It works just as well for earthenware. 
As I knock some rust off I'll be pushing to try and make more complex molds that would allow me to cast Porthos as whole and as close to one piece as possible.  Body with three legs attached most likely, with the head and neck separate and that cocked back leg.  That would take less assembly and thus less time.  And problem solving with mold making is an excellent challenge to practice if you want to get better anyway.
One of my new sculptures I have started is the 'Spider foal' that is rolling.   I'm jokingly calling it my 'spider' sculpture for now because it looks hideous!  But it's in the early 'skeleton' stage where I flesh out the proportions of the bones and set the joints as points of reference from which I will build up tendons, muscle, skin, etc over top.  Anyway, you can see that I do not like to sculpt with molding limitations in mind.  So being able to mold them in pieces and assemble ANY kind of pose or complex arrangement really frees me up to do anything I want.  

Thank you!  Speaking of Fabio tails... With a really complex tail such as my hairy Pasture Porthos sports I may well need to cut the tail into at least two pieces and have quite a few mold pieces /and/ still have to flood, then redetail, some of the undercuts.  Oh well!  This boy will be my most challenging piece to mold to date (this is a 3D print that is mirrored to face the other direction and a different size).  For now I am cheating.  I sent this boy and his larger version off to England to be molded and cast in bone china bisque for me.  But I will be playing with cutting one up here in studio and trying to mold that tail myself just for the challenge.  BUT at least I know he'll be in production in time for Breyerfest in July even if it takes me a while to mold and cast this version on my side of the pond.
For scale I can do pretty much anything I want within the limits of my 3D printers and the quality of my scans.  Or in the case of the spider foal - larger than 'traditional' scale because I'm doing that one BIGGER than usual.  But 'traditional' scale is what most equine bronzes are normally produced in - 1/9th scale to the real horse.  Larger than traditional is usually about 1/6th scale.  Classic is about 1/12th, etc on down or on up!  Some of these scales are used so often for equine art that they have names (though often more than one name for any given size).  Porthos is considered 1/9th scale, which usually is about 7 inches tall.  But as he's a draft horse who's taller and larger his scaling down to 1/9th came to 8 inches tall.  Of course he'll shrink a bit in each ceramic media, that's just his resin size.    If you do internet searches you can find various 'model scales' or 'model horse scales' to compare.
'Venti' scale Pasture Porthos is a little smaller than 'classic' scale at 1/15th is shown with the larger roto cast white resin that is 1/9th 'traditional' scale.  Then micros are about 1/40th scale (around 1.5" tall).  Curio falls in around 1/20th scale for comparison (not pictured here).